Women's choice. As the intensity and demands on time increase in a highly competitive field, women choose a different lifestyle other than that as a coach, where experience shows that as an assistant you move constantly and have little job security. Most women are more risk-averse than men.
One of those wonderful things about biology; they're different, complementary, but different nonetheless.
I do not buy the risk-averse argument in the least. It's not a choice. That is a ridiculous argument, imo.
I fought long and hard back in the 70's to get a job when I had been told I wasn't qualified because CPA's did not like dealing with women. That set me on fire and I fought and won. Funny thing was I knew my career in that city was over, so I transferred to the Denver office. I was totally shocked the first time I went to training and there were all kinds of women doing the job I had been told CPA's didn't like to deal with. It was management's opinion in the city I left that women should not be in the job. Another woman who did not get promoted also fought and got back pay. Yes, there then followed a change in management. Today, there are probably more women than men in that position. Funny how that worked out.
Yes, we are different than men, but your argument does not hold water. There has never been any job security, especially if you are an assistant coach, in coaching of any sort. When the head coach leaves for any reason, if you are unable to follow them, you are job hunting. It's always been like that.
When Coach Barry retired, she was able to put her long time director of basketball operations in to the position of what is now the Associate AD/Student Services. Tracy Tripp was the director of basketball operations for KMM and she is now in the athletic department in HR.
An assistant coach for Coach Barry, Karen Morrison, who is one of the brightest women I've ever met, left coaching when she and her partner adopted young children. She moved over to the Athletic Department as an Associate Athletic Director/SWA. She then spent 8 years with the NCAA and is now at the University of Central Florida. Without her father, the University of Oklahoma may not have a women's basketball program today. In March of 1990, OU tried to drop women's basketball. Her father was a big donor as well as fan (except when they played Colorado) and 8 days later the program was reinstated. OU took a chance with Sherri Coale and look what has happened since!